Tube connector

ABSTRACT

A U-shaped tube-connecting clip is provided having a substantially rectangular configuration formed from strip material, the U-shaped clip having a substantially flat bottom at its bight with a pair of legs depending upwardly from opposite edges of the said bight, the free edges of the bight being in the form of extending ledges for interference engagement with a rectangular tube upon axial assembly thereof. The legs of the clip are provided with indexing shoulders for contacting the end of the receiving tube during assembly, the tube being provided with lanced detents on opposite walls thereof in the form of inwardly projecting snap retention shoulders which provide spring-biased engagement with the ledges of the clip following the insertion thereof.

Beals [451 Feb. 18,1975

[ TUBE CONNECTOR [75] Inventor: Max D. Beals, Riverside, Calif.

[73] Assignee: Amax Aluminum Company, Inc.,

San Mateo, Calif.

22] Filed: Mar. 25, 1974 [21] Appl. No.: 454,288

[52] US. Cl. 403/190, 403/235 [51] Int. Cl. Fl6b 9/00 [58] Field ofSearch 403/234, 237, 232, 233,

Primary Examiner-Andrew V. Kundrat Attorney, Agent, or Firml(asper T.Serijan; Eugene J. Kalil [5 7] ABSTRACT A U-shaped tube-connecting clipis provided having a substantially rectangular configuration formed fromstrip material, the U-shaped clip having a substantially flat bottom atits bight with a pair of legs depending upwardly from opposite edges ofthe said bight, the free edges of the bight being in the form ofextending ledges for interference engagement with a rectangular tubeupon axial assembly thereof. The legs of the clip are provided withindexing shoulders for contacting the end of the receiving tube duringassembly, the tube being provided with lanced detents on opposite wallsthereof in the form of inwardly projecting snap retention shoulderswhich provide spring-biased engagement with the ledges of the clipfollowing the insertion thereof.

7 Claims, 8 Drawing Figures PAHNTEB FEB] 81975 TUBE CONNECTOR Thisinvention relates to a U-shaped tube-connecting clip and totube-connecting assemblies thereof.

STATE OF THE ART It is known to assemble square metal tubing (e.g.aluminum tubing) into framework for lightweight building construction.Generally, the tube ends are notched by hand to leave one or two cartabs for use in coupling the tube parts together. Angle brackets or flatsplice plates are also used.

The foregoing methods have certain disadvantages. For one thing, it istime consuming in the field or at the factory to measure the tube endsfor notching. In addition, the tabs are not generally provided withholes for receiving a starting screw. Moreover, if the notch is notcarefully made, the joint has a poor appearance and generally does nothave good strength, especially where the tab is the same thickness asthe wall thickness of the tube.

It would be desirable to provide a simple mechanical means of easilysecuring an end of rectangular tubing (e.g. square tubing) to the sideand at an angle (e.g. at right angles) to another tube either in thefield or in the factory.

The present invention overcomes the foregoing disadvantages and providesa new and improved U-shaped tube-connecting clip for producingsubstantially rigid joints from tubes of rectangular cross section,particularly tubes of square cross section.

OBJECTS OF THE INVENTION It is thus the object of the invention toprovide a tubeconnecting clip capable of being used in the field as wellas at the factory in producing lightweight frame structures.

Another object is to provide a tube-connecting assembly in which aU-shaped tube-connecting clip is employed as a means ofproducing asubstantially rigid assembly.

A further object is to provide a mechanical joint between two tubes ofrectangular cross section.

These and other objects will more clearly appear when taken inconjunction with the following disclosure and the accompanying drawing;wherein:

FIG. 1 is illustrative ofa tube assembly in perspective involving twosquare tube portions connected at right angles to each other via theU-shaped tube-connecting clip of the invention;

FIG. 2 is a three-dimensional exploded view of the cooperating elementsof FIG. 1;

FIG. 3 is a cross section of the assembly of FIG. 1 taken along lines3-3 at the mechanical joint;

FIGS. 4 to 6 illustrate the sequential steps in the insertion of theU-shaped clip into an end of a square tube;

FIG. 7 is illustrative of one form of a U-shaped clip in which one ofthe legs is bent at right angles to itself for use in the mountingthereof on a surface; and

FIG. 8 is an assembly similar to FIG. 1 except that the rectangularcross section has a shape of an elongated rectangle.

STATEMENT OF THE INVENTION The invention provides a U-shapedtube-connecting clip of substantially rectangular configuration, theclip being formed from strip material and comprising a substantiallyflat web or platform at its bight with a pair of spaced legs integralwith the opposite edges of said bight and extending upwardly therefrom,the remaining free edges of the bight being in the form of extendingledges.

Each of the legs of the clip has an inwardly projecting indexingshoulder formed laterally thereon at substantially the same distance asthe other, the shoulders serving as indexing stop means when the clip isinserted into the open end of a conforming rectangular tube.

In order to provide a locking mechanism for a tube gagement with theextending ledges of said clip when the clip is force-fitted into therectangular tube past said means. The lanced detents are located apredetermined distance in from the end of the tube and correspondsubstantially to the distance between the indexing shoulders of theU-shaped clip and the bight of the clip; that is to say, the distance ofthe lanced detents from the tube end is determined to provide sufficientplay to enable the inserted clip to lock in place. The foregoingmechanism will be clearly apparent from the figures of the attacheddrawing.

FIG. 1 is a perspective view of a joint assembly referred to generallyby numeral 10 comprising rectangular tube portion 11 mechanically joinedat right angles to rectangular tube portion 12 (the tubes have a squarecross section) by means of U-shaped clip 13. The opposite walls of tube12 are provided with lanced detents 14 as shown. The two tubes areformed from strip material, e.g. metal strip, such as aluminum, byfolding over together the longitudinal edges of the strip to form lockseams 11a and 12a as shown.

The elements making up the mechanical joint of FIG. 1 are shown moreclearly in the exploded view of FIG. 2 which depicts U-shaped clip 13comprising a substantially flat web or platform at bight 15 with a pairof legs 16, 17 integral therewith and extending from the platformsubstantially at right angles therefrom. As will be noted, the legs areindented with a substantially right angle bend intermediate the lengththereof to provide indexing shoulders 16a and 17a. The free edges of thebight extend outwardly as ledges 18, 19 and are designed to makeinterference contact with lanced detents 14 and 14a of FIG. 2. By lanceddetents is meant that slit openings are formed as shown in FIG. 2 sothat the detents are in the form of inwardly projecting, snapretentionshoulders shown more clearly in FIG. 3 which is a cross section takenalong line 33 of FIG. 1, the snap-retention shoulders providingspring-biased engagement with the ledges of the U-shaped clip when theclip is force-fitted into the rectangular tube past said shoulders asshown in the operation sequence of FIGS. 3 through 6. The platform orweb at the bight 15 is provided with a deformed elongated dimple 20 tostiffen it by increasing its cross sectional modulus. The legs areprovided with holes to receive sheet metal screw 21 also shown inFIG. 1. The legs of the clip will generally have a larger gage size thanthe tube material. For example, if the tube material has a gage of 0.03inch, then The length and width of platform or web of the bight 15 iscalculated to slide within the tube and make interference contact withthe snap-retention shoulders of the tube.

Thus, as will be noted in FIG. 3, the U-shaped clip with the extendingledges 18, 19 is inserted into the end of tube 12 and the ledges causedto make interference engagement with the snap-retention shoulders 14 and14a until the ledges clear the shoulders and lock in place by thespring-biased action of said shoulders as shown. In the meantime, theindexing shoulders of the legs of the clip contact the end of the tubeas a stop, thereby providing a fairly rigid mechanical joint followingsnap engagement of the two elemental parts together.

The sequential steps of inserting the clip are shown in FIGS. 4 to 6.Note in FIG. 5 the partial insertion of the clip with ledge 18 makinginterference engagement with snap-retention shoulder 14 until the ledgeclears the shoulder and is locked thereby as shown in FIG. 6. In themeantime, indexing shoulder 17a on the leg 17 of the clip strikesagainst the end of tube 12 as the ledge clears the snap-retentionshoulder. This is also shown in FIG. 1.

Another modification of the U-shaped clip 13a is shown in FIG. 7 inwhich one of the legs thereof is made longer than the other and bent atright angles to itself to provide a mounting tab 22 so that the cliptogether with its connected tube shown phantomly by numeral 23 isfastened to a surface at right angles to the longitudinal axis of thetube.

The term "rectangular shape employed herein is meant to include any foursided right angle shape such as an elongated rectangle or a square.

A tube assembly having a cross section which defines an elongatedrectangle is shown in FIG. 8 comprising tubes 24, 25 coupled at rightangles to each other using the U-shaped clip 26 of the invention, thelegs of the clip being fastened to tube 24 via a sheet metal screw 28.Lanced detents 27 are provided on opposite walls of tube 25 in the formof inwardly projecting, snapretention shoulders as illustrated in FIGS.4 to 6.

In addition to providing a tube-connecting assembly, the invention alsoprovides a mechanical joint comprising one rectangular tube joined at anangle to another rectangular tube.

The joint comprises a first tube portion of rectangular configurationhaving connected thereto a U-shaped clip having a pair of legs whichembraces the first tube portion transversely and is fastened thereto(note FIG. 1). The U-shaped clip has a substantially rectangularconfiguration and has a platform or web at its bight with the legsdepending from opposite edges thereof, the free edges of the bightbetween the legs being in the form of extending ledges. Each of the legshas indexing shoulders laterally formed therein at the same distancefrom the bight.

The bight end is inserted axially into a second rectangular tube portionto provide a substantially right angle joint (FIG. 1), the tube havinginwardly projecting snap-retention means which lockingly engage theledges of the bight.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and the appended claims.

What is claimed is:

l. A mechanical joint comprising one rectangular tube joined at an angleto another, said joint comprising,

a first hollow tube portion of rectangular configuration, a U-shapedtube-connecting clip having a pair of legs which embraces transverselysaid first tube portion with the legs fastened thereto. said U-shapedtube-connecting clip being of substantially rectangular configurationand having a substantially flat platform or web at its bight with saidpair of legs depending from opposite edges of said bight, the free edgesof said bight between the legs being in the form of extending ledges,

each of said legs having indexing shoulders laterally formed therein ata predetermined distance from said bight,

a second rectangular hollow tube portion having an open end into whichthe bight end of said clip is inserted in interference engagementtherewith having inwardly projecting snap-retention means which providespring-biased engagement with the free ledges of said clip following theinsertion thereof, said snap-retention means being located apredetermined distance in from the open end of the tube correspondingsubstantially to the said predetermined distance between the indexingshoulders of the U-shaped clip and the bight thereof, such that asubstantially rigid mechanical joint is formed in which the indexingshoulders of the clip are held firmly against the end of said secondtube with the ledges of the bight in engagement with the snap-retentionmeans of the tube by virtue of the spring-biased action of saidsnapretention means.

2. The mechanical joint of claim 1, wherein the inwardly projectingsnap-retention means of said second tube portion comprise lanceddetents.

3. The mechanical joint of claim 1, wherein the rectangular tubesforming the joint have a substantially square cross section.

4. A tube-connecting assembly comprising a hollow rectangular tubeportion with a U-shaped tubeconnecting clip snap-fitted therein,

said U-shaped tube-connecting clip being of substantially rectangularconfiguration and having a substantially flat platform at its bight witha pair of spaced legs depending from opposite edges of said bight withthe free edges of said bight between the legs being in the form offreely extending ledges, at least one of said legs having an indexingshoulder laterally formed therein at a predetermined distance from saidbight,

said rectangular hollow tube portion receiving the bight end of saidclip in axial snap-fitted engagement therewith, said tube portion havinginwardly projecting snap-retention means located on opposite walls ofsaid tube which provide spring-biased engagement with the free ledges ofsaid clip, said snap-retention means being located a predetermineddistance in from the open end of the tube corresponding substantially tosaid predetermined distance between the at least one indexing shoulderof the U-shaped clip and the bight thereof,

such that the tube-connecting assembly is characterized in that the saidat least one indexing shoulder of the clip engages the end of the tubewith the free ledges of the bight engaging the snap-retention means ofthe tube by virtue of the spring-biased action of said snap-retentionmeans thereby forming a substantially rigid tube connection.

5. The tube-connecting assembly of claim 4, wherein said rectangulartube portion has a substantially square cross section.

6. A tube-connecting assembly comprising a hollow rectangular tubeportion with a U-shaped tubeconnecting clip snap-fitted therein,

said U-shaped tube-connecting clip being of substantially rectangularconfiguration and having a substantially flat platform at its bight witha pair of spaced legs depending from opposite edges of said bight, thefree edges of said bight between the legs being in the form of freelyextending ledges,

at least one of said legs having an indexing shoulder laterally formedtherein at a predetermined distance from said bight,

said rectangular hollow tube portion receiving the bight end of saidclip in-axial snap-fitted engagement therewith, said tube portion havinglanced detents on opposite walls of said tube in the form of inwardlyprojecting snap-retention shoulders which provide spring-biasedengagement with the free ledges on the bight of said clip, saidsnapretention shoulders being located a predetermined distance in fromthe open end of the tube corresponding substantially to thepredetermined distance between the at least one indexing shoulder of theU-shaped clip and the bight thereof, such that the tube-connectingassembly is characterized in that the said at least one indexingshoulder of the clip engages the end of the tube with the free ledges ofthe bight engaging the snap-retention shoulders of the tube by virtue ofthe spring-biased action of said snap-retention shoulders, therebyforming a substantially rigid connection.

7. The tube-connecting assembly of claim 6, wherein said rectangulartube portion has a substantially square cross section.

1. A mechanical joint comprising one rectangular tube joined at an angleto another, said joint comprising, a first hollow tube portion ofrectangular configuration, a U-shaped tube-connecting clip having a pairof legs which embraces transversely said first tube portion with thelegs fastened thereto, said U-shaped tube-connecting clip being ofsubstantially rectangular configuration and having a substantially flatplatform or web at its bight with said pair of legs depending fromopposite edges Of said bight, the free edges of said bight between thelegs being in the form of extending ledges, each of said legs havingindexing shoulders laterally formed therein at a predetermined distancefrom said bight, a second rectangular hollow tube portion having an openend into which the bight end of said clip is inserted in interferenceengagement therewith having inwardly projecting snap-retention meanswhich provide spring-biased engagement with the free ledges of said clipfollowing the insertion thereof, said snapretention means being locateda predetermined distance in from the open end of the tube correspondingsubstantially to the said predetermined distance between the indexingshoulders of the U-shaped clip and the bight thereof, such that asubstantially rigid mechanical joint is formed in which the indexingshoulders of the clip are held firmly against the end of said secondtube with the ledges of the bight in engagement with the snap-retentionmeans of the tube by virtue of the spring-biased action of saidsnap-retention means.
 2. The mechanical joint of claim 1, wherein theinwardly projecting snap-retention means of said second tube portioncomprise lanced detents.
 3. The mechanical joint of claim 1, wherein therectangular tubes forming the joint have a substantially square crosssection.
 4. A tube-connecting assembly comprising a hollow rectangulartube portion with a U-shaped tube-connecting clip snap-fitted therein,said U-shaped tube-connecting clip being of substantially rectangularconfiguration and having a substantially flat platform at its bight witha pair of spaced legs depending from opposite edges of said bight withthe free edges of said bight between the legs being in the form offreely extending ledges, at least one of said legs having an indexingshoulder laterally formed therein at a predetermined distance from saidbight, said rectangular hollow tube portion receiving the bight end ofsaid clip in axial snap-fitted engagement therewith, said tube portionhaving inwardly projecting snap-retention means located on oppositewalls of said tube which provide spring-biased engagement with the freeledges of said clip, said snap-retention means being located apredetermined distance in from the open end of the tube correspondingsubstantially to said predetermined distance between the at least oneindexing shoulder of the U-shaped clip and the bight thereof, such thatthe tube-connecting assembly is characterized in that the said at leastone indexing shoulder of the clip engages the end of the tube with thefree ledges of the bight engaging the snap-retention means of the tubeby virtue of the spring-biased action of said snap-retention meansthereby forming a substantially rigid tube connection.
 5. Thetube-connecting assembly of claim 4, wherein said rectangular tubeportion has a substantially square cross section.
 6. A tube-connectingassembly comprising a hollow rectangular tube portion with a U-shapedtube-connecting clip snap-fitted therein, said U-shaped tube-connectingclip being of substantially rectangular configuration and having asubstantially flat platform at its bight with a pair of spaced legsdepending from opposite edges of said bight, the free edges of saidbight between the legs being in the form of freely extending ledges, atleast one of said legs having an indexing shoulder laterally formedtherein at a predetermined distance from said bight, said rectangularhollow tube portion receiving the bight end of said clip in axialsnap-fitted engagement therewith, said tube portion having lanceddetents on opposite walls of said tube in the form of inwardlyprojecting snap-retention shoulders which provide spring-biasedengagement with the free ledges on the bight of said clip, saidsnap-retention shoulders being located a predetermined distance in fromthe open end of the tube corresponding substantially to thepredetermined distance betWeen the at least one indexing shoulder of theU-shaped clip and the bight thereof, such that the tube-connectingassembly is characterized in that the said at least one indexingshoulder of the clip engages the end of the tube with the free ledges ofthe bight engaging the snap-retention shoulders of the tube by virtue ofthe spring-biased action of said snap-retention shoulders, therebyforming a substantially rigid connection.
 7. The tube-connectingassembly of claim 6, wherein said rectangular tube portion has asubstantially square cross section.